1. Field of the Invention
This invention relates to a quick release valve, primarily for use in a vehicle braking system to control the flow of actuating fluid under pressure to one or more brake actuators.
2. Description of the Prior Art
Such a valve is employed particularly in pneumatically operated braking systems and operates to permit the rapid decay of braking pressure to atmosphere via an exhaust port when the primary supply pressure is removed after braking i.e. in the "brakes off" condition. A freely movable diaphragm of the valve closes the exhaust port during braking but is moved away from the port by the brake line pressure upon brake release to permit air flow therethrough from the brake line and so cause the aforesaid decay of pressure. Such rapid release valves often give rise, during pressure decay, to loud hissing and other noises due to oscillation of the diaphragm, which is thought to result from an interaction between the inherent resilience of the diaphragm and the falling air pressure in the delivery lines. Such noises can be disconcerting when they occur in close proximity to unsuspecting people, as for example in a crowded street.